The Lord of the Rings / The Hobbit movies. If I could manage it usually would head up to the theater to re-watch every 1-2 weeks.
They were all movies released in December. I still distinctly remember heading up to the IMAX in Manhattan late night after work so the movie would finish up around midnight(?). After watching these movies I'd walk out of the theater into a cold and snowy NYC. Felt a bit surreal, especially after the last 2 Hobbit movies where most of the movies were centered around cold climates.